Siemens Aktiengesellschaft

Martina Vogt

Wolfram Wersing

Karl Lubitz

Hans Kaarmann

Jutta Mohaupt

Ulrich Bast

Dieter Cramer

Reinhard Lerch

Ernst Fenner

A composite ultrasound transducer (array) contains piezoelectric ceramic transducer elements which radiate substantially in the longitudinal direction, and are embedded in a polymer matrix. The transducer elements have such a geometrical structure, and are arranged relative to each other, so that the development of oscillation modes perpendicular to the longitudinal direction of the transducer elements is suppressed. A method for manufacturing the composite ultrasound transducer includes the steps of filling a plastic form, having a 'negative' of the desired shape of the transducer elements, with ceramic slurry, and pyrolyzing the plastic form after the slurry dries therein. The resulting voids between the hardened ceramic elements are filled with polymer to create the overall composite transducer. The transducer elements can thus be given an arbitrary shape and arrangement, such as hexagonal or irregular square structures, having a trapezoidal cross-section in planes parallel to the longitudinal axis of the transducer elements.

Composite ultrasound transducer and method for manufacturing a

An ultrasound array has a number of oscillator elements arranged side-by-side, each oscillator element having a trapezoidal cross-section. The oscillator elements are separated from each other by incisions having non-parallel walls, which are co-planar with surfaces of the piezoelectric material comprising the oscillator element. The incisions terminate in a damping member, to which all of the oscillator elements are attached. The incisions are produced with an excimer laser whose laser beam is focused onto a prepared layered material, with the incisions proceeding along a line.

Ultrasound array having trapezoidal oscillator elements and a method and

A piezoelectric ceramic powder is, together with a binder, processed to a granulate. This granulate is mixed with a pearl polymer to a mixture. The mixture is pressed to a suitable shape, and then in a first firing step the binder and the pearl polymer are fired out. Preferably the first firing process is followed by a second firing step for sintering. Thereafter mechanical fabrication may take place, to give the end product its shape. The firing out of the pearl polymer results in a porous piezoelectric ceramic, with which, when used in an ultrasonic transducer, a high transducer effectiveness, sharp ultrasonic pulses with little edge radiation as well as a good electric and acoustic adaptation can be achieved.

Porous piezoelectric material and method for making it

An adaptation layer for an ultrasound applicator which contains a mixture of synthetic resin and ceramic powder. Through the addition of ceramic powder, the acoustic impedance of the applicator can be easily adjusted. Impedance values selectable in the range of e.g., 6 to 12.times.10.sup.6 kg/m.sup.2 sec are possible.

Adaptation layer for an ultrasound applicator

A material is disclosed for use as an adaptation layer in ultrasonic transducer units of the type which have a piezo-ceramic transducer. The material is porous, and the acoustic impedance of the material can be adjusted (in one embodiment, to 12.times.10.sup.6 kg/cm.sup.2 s) by adjusting the porosity of the material. In preferred embodiments, the material is piezo-electric and may have a porosity gradient.

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Fuerth, Germany

Martina Vogt